GHK-Cu Injection Dosage: What the Research Used and What Protocols Look Like

Every GHK-Cu injection dosage in circulation is a convention rather than a measurement. There is no published human trial of GHK-Cu alone by injection, no dose finding study and no pharmacokinetic paper that we could locate on PubMed as of September 2026; the one injected series in people used it inside a growth factor cocktail, covered below. The 1 to 2 mg figure that appears on vendor pages, in forum protocols and in the Bureau's own GHK-Cu guide did not come from a conversion of animal data the way the BPC-157 numbers did. It is simply the amount people settled on.

That is worth knowing before reading any protocol, including the ones below. This page sets out what the injectable research actually used, how the common figures relate to it, the decisions that change a protocol more than the number does, where people inject, and the arithmetic that turns a 50mg vial into syringe units. Safety by route has its own page at GHK-Cu side effects, and the topical form, which has both of the controlled human trials, is covered at topical GHK-Cu.

Where the Injection Numbers Come From

GHK was identified in 1973 as a fraction of human albumin that made old liver tissue synthesise protein like young tissue (Pickart et al., Oxid Med Cell Longev 2012, PMID 22666519). It binds copper with an affinity close to albumin's own copper transport site, and the complex, GHK-Cu, is what the injectable research used. The animal work that followed was mostly wound healing, and the injection data inside it is thinner than the citation count suggests.

The clearest injected figure in the literature is from a 1999 rat study in the Journal of Investigative Dermatology (Siméon et al., PMID 10383745). Wound chambers were implanted under the skin of rats and received serial injections of 2 mg GHK-Cu or saline, and the peptide altered which matrix metalloproteinases were expressed and activated in the healing tissue. That 2 mg was injected into a chamber at the wound, in an animal weighing a few hundred grams. It is local, not systemic, and it cannot be scaled to a human body by surface area or by weight. Anyone who tells you the human dose was derived from it is guessing.

Pickart's reviews report that GHK-Cu induces systemic wound healing in rats, mice and pigs (Biomed Res Int 2015, PMID 26236730), and a 2016 mouse study found that GHK-Cu reduced inflammatory signalling and tissue damage in lipopolysaccharide induced lung injury (Park et al., Oncotarget 2016, PMID 27517151). Neither abstract states a milligram per kilogram dose, and the review author's affiliation is a skincare company founded by the discoverer, which is not disqualifying but is worth knowing when reading the strength of the language.

Two controlled human trials of GHK-Cu exist and both are topical. A multicentre randomised, evaluator blinded, placebo controlled study in diabetic neuropathic foot ulcers reported a median 98.5 percent closure with a GHK-Cu gel against 60.8 percent for vehicle, and a 7 percent infection rate against 34 percent (Mulder et al., Wound Repair Regen 1994, PMID 17147644). The second randomised patients to a GHK-Cu skin care regimen or the same regimen without it after CO2 laser resurfacing around the mouth; in the 13 who completed it, blinded evaluators found no difference in erythema resolution and no objective difference in wrinkles or skin quality at 12 weeks, and only patient satisfaction was higher in the GHK-Cu group (Miller et al., Arch Facial Plast Surg 2006, PMID 16847171). Neither says anything about injections, but the ulcer trial is the reason GHK-Cu is taken seriously at all.

The Decisions That Change the Protocol

Four choices, in the order that matters.

Route: subcutaneous, local, or not injected at all

Subcutaneous injection into abdominal fat is what a GHK-Cu injection almost always means, and it is the route with systemic intent: the peptide is meant to reach skin everywhere, connective tissue and whatever else it acts on, rather than one patch of it. Local injection is a different practice. Some clinics inject small amounts across the scalp or face in a mesotherapy pattern, and the hair loss page describes the 0.1 to 0.2 mg per site figures that circulate for it. The one published human series of injected GHK-Cu used it as one ingredient of a six component growth factor cocktail injected intradermally into the scalp, open label and uncontrolled, in 1,000 patients (Kapoor and Shome, J Cosmet Laser Ther 2018, PMID 29482481); it reported the treatment as well tolerated and says nothing about GHK-Cu on its own or about subcutaneous systemic use. There is no trial of GHK-Cu alone by either local route in humans.

The third option is to not inject. The mechanism data suggests GHK-Cu works at nanomolar concentrations in the tissue it touches, and both human trials were topical. For a skin goal, the honest question is whether a topical route reaches the dermis well enough, which is a delivery problem covered on the topical page, not a dose problem.

Frequency: daily or three times a week

Both appear in circulation and the Bureau's guide has, at different points, described each. No human pharmacokinetic study of injected GHK-Cu has been published, so nobody can say how long a dose stays in plasma. What is known is that GHK is a normal constituent of human plasma whose level falls with age (Pickart et al. 2015, PMID 26236730), which is the usual argument for smaller, more frequent doses that keep a level rather than large infrequent ones. Daily injection at 1 mg and three times weekly at 2 mg deliver 7 mg and 6 mg a week respectively, which is not a meaningful difference; the choice is mostly about tolerance for injections and, for some people, the sting.

Cycle length

Four to eight weeks on, then a break of similar length, is the pattern in circulation. Unlike the growth hormone secretagogues there is no receptor desensitisation argument that forces it. The reason to keep a break anyway is copper, covered next, and the general principle in the cycle length guide that an unstudied compound gets the conservative schedule.

Total dose and the copper it carries

This is the part of GHK-Cu dosing that is genuinely different from other peptides. GHK-Cu is roughly 16 percent copper by mass: the tripeptide weighs about 340 daltons and the copper ion about 64, so a 1 mg dose delivers about 0.16 mg of copper and a 2 mg dose about 0.3 mg. For scale, the adult dietary reference intake for copper is 0.9 mg a day and the tolerable upper intake level is 10 mg a day, as set by the US Institute of Medicine in 2001. A daily 2 mg injection adds a third of the recommended dietary amount and about a thirtieth of the upper limit.

Two caveats stop that from being fully reassuring. Injected copper bypasses the intestinal absorption step that regulates how much dietary copper the body takes up, so dietary comparisons overstate the margin. And anyone with Wilson's disease or another copper handling disorder should not be adding copper by any route. The side effects page goes through this properly.

Protocols in Circulation

These are descriptions of what appears in practice, presented as research use information rather than as instructions. None of them is validated in a human trial, and the amounts are the conventions discussed above, not the output of a dose response study.

The pattern is the same as for BPC-157: the amount barely moves between goals while the duration does. That reflects a literature that gives a reason to think GHK-Cu does something across a wide range of exposures and almost no guidance on where in that range to sit.

The blend row needs care. The KLOW and GLOW vials are sold by total mass, and in the common 80 mg KLOW format 50 mg of that is GHK-Cu. A 4 mg dose of the blend is therefore 2.5 mg of GHK-Cu plus 0.5 mg each of the other three compounds, and the copper arithmetic above applies to the 2.5 mg, not the 4.

Where to Inject GHK-Cu

What appears in practice is subcutaneous injection into a pinch of fat on the abdomen a few centimetres from the navel, the outer thigh, or the back of the upper arm, rotating between sites so that no spot is used twice in a row. That is the same pattern as for any research peptide, and the injection guide covers needle choice, angle and technique. Two things are specific to GHK-Cu.

The first is colour. GHK-Cu in solution is blue to violet, because copper(II) complexes are, and a subcutaneous injection sometimes leaves a faint blue tint at the site for a few hours. It is the compound, not a bruise, and it clears. The second is the sting. GHK-Cu is widely reported to burn on injection, which is not a common complaint with most research peptides, and no published explanation exists. The two practical responses in circulation are to reconstitute with more bacteriostatic water so the same milligram dose is spread through a larger, less concentrated volume, and to inject slowly. Both are low risk and both are anecdote.

Injecting near the target, into the face or scalp, is the mesotherapy practice mentioned above. The systemic route already reaches the skin, the local route's only human data is the uncontrolled cocktail series above, and putting a needle into the face is a job for someone who does it professionally. The Bureau does not describe a home protocol for it.

Turning a 50mg Vial Into Syringe Units

GHK-Cu doses are quoted in milligrams and vials are labelled in milligrams, which removes the thousandfold microgram error that haunts BPC-157. The remaining arithmetic is concentration. Concentration is vial milligrams divided by millilitres of bacteriostatic water added; volume per dose is the dose divided by that concentration; units on a U-100 insulin syringe are that volume in millilitres multiplied by 100.

The rows to avoid are the concentrated ones. A 1 mg dose at 4 units is measurable but a one unit misread is a 25 percent error, and diluting further is also the usual answer to the sting. Adding water addresses both without changing how much compound is delivered, provided the vial has the headroom; a 50mg vial in a 3 mL bottle cannot take 5 mL, and a 10 mL bottle can. Bacteriostatic water is the usual diluent and the bac water guide covers why; the reconstitution guide covers the mixing itself and how long the mixed vial keeps in the fridge.

Injected, Topical, or Both

What can be said from the data is that the two routes are answering different questions: topical asks whether the peptide gets in, injected asks what it does once it is everywhere. The guide's view that running both together gives the strongest reported results is a report, not a test.

Where the Assumptions Go Wrong

• Treating the rat wound chamber's 2 mg as a human dose. It was a local injection in an animal weighing a few hundred grams. The coincidence with the community figure is a coincidence.
• Confusing blend mass with GHK-Cu mass. Four milligrams of KLOW is 2.5 mg of GHK-Cu.
• Assuming a nutrient is harmless in any amount. Copper is essential and also has an upper intake limit for a reason, and injected copper skips the gut's regulation.
• Assuming label weight is peptide weight. Lyophilised powder is typically 70 to 90 percent peptide by mass, with the balance water and counterions, which the testing guide covers. GHK-Cu specifically can also be sold under-coppered, as free GHK with too little copper, and a COA that reports copper content is the only way to catch it.
• Judging skin results at two weeks. Collagen remodelling is measured in months; the guide's own timeline puts visible texture change in the second and third month.

Key Takeaways

• No human trial of GHK-Cu alone by injection exists on PubMed; the one injected series was a scalp cocktail, and the 1 to 2 mg figure is a convention, not a converted dose
• The clearest injected research figure, 2 mg into rat wound chambers, was local and cannot be scaled to a person
• GHK-Cu is about 16 percent copper, so a 2 mg dose carries about 0.3 mg of copper, a third of the dietary reference intake, delivered without the gut's regulation
• Route, frequency and cycle length change the protocol more than the milligram figure does
• Reconstituting dilute, 10 mg/mL, puts 1 mg at 10 units and is the usual answer to the sting
• The blue tint at the injection site is the compound's colour, not a bruise
• Blend vials are sold by total mass; do the GHK-Cu arithmetic on the GHK-Cu fraction

Frequently Asked Questions

What is the typical GHK-Cu injection dosage?

The figure in circulation is 1 to 2 mg per subcutaneous injection, given between three times a week and daily, in blocks of four to eight weeks. It is a convention rather than a measured dose: no human dose finding trial of injected GHK-Cu has been published, and the clearest injected figure in the animal literature, 2 mg into implanted wound chambers in rats, was a local injection that cannot be scaled to a person. Treat the range as a description of practice, not a recommendation.

How often is GHK-Cu injected?

Both daily and three times weekly schedules are common, and over a week they deliver a similar total, 7 mg at 1 mg daily against 6 mg at 2 mg three times weekly. There is no published human pharmacokinetic study to say which pattern better matches how long the peptide persists, so the choice in practice comes down to tolerance for injections and, for some people, the sting that GHK-Cu is known for.

Where do you inject GHK-Cu?

Subcutaneously, into abdominal fat a few centimetres from the navel, the outer thigh or the back of the upper arm, rotating sites. Local injection into the scalp or face is a clinic mesotherapy practice; the only human data is an uncontrolled 1,000 patient series of a growth factor cocktail that contained copper tripeptide-1, not GHK-Cu on its own, and it is not something the Bureau describes as a home protocol. The systemic route reaches the skin everywhere in any case.

Why does GHK-Cu sting and turn the skin blue?

The blue is the compound itself: copper(II) complexes are blue to violet in solution, and a little of it sitting under the skin shows through for a few hours before it disperses. The sting is widely reported and has no published explanation. The two practical responses in circulation are to reconstitute with more bacteriostatic water, so that the same dose is spread through a larger and less concentrated volume, and to inject slowly.

How much copper is in a GHK-Cu dose?

About 16 percent of the mass. The tripeptide weighs roughly 340 daltons and the copper ion roughly 64, so a 1 mg dose carries about 0.16 mg of copper and a 2 mg dose about 0.3 mg. The adult dietary reference intake for copper is 0.9 mg a day and the tolerable upper intake level is 10 mg a day, though injected copper bypasses the intestinal regulation that those dietary figures assume. Anyone with Wilson's disease or another copper handling disorder should not be adding copper by any route.